The radiation environment in a Low Earth Orbit: the case of BeppoSAX

TL;DR

This study analyzes the radiation environment in Low Earth Orbit using data from the BeppoSAX satellite, focusing on the South Atlantic Anomaly's characteristics and variations over time.

Contribution

It provides detailed measurements and analysis of the SAA's intensity, extent, drift, and dependence on altitude and magnetic rigidity in a low-inclination LEO.

Findings

SAA intensity decreases with altitude

SAA extent and drift vary over time

SAA strength depends on magnetic rigidity

Abstract

Low-inclination, low altitude Earth orbits (LEO) are of increasing importance for astrophysical satellites, due to their low background environment. Here, the South Atlantic Anomaly (SAA) is the region with the highest amount of radiation. We study the radiation environment in a LEO (500-600 km altitude, 4 degrees inclination) through the particle background measured by the Particle Monitor (PM) experiment onboard the BeppoSAX satellite, between 1996 and 2002. Using time series of particle count rates measured by PM we construct intensity maps and derive SAA passage times and fluences. The low-latitude SAA regions are found to have an intensity strongly decreasing with altitude and dependent on the magnetic rigidity. The SAA extent, westward drift and strength vs altitude is shown.